Assembly and method for transferring imprint lithography templates

ABSTRACT

Disclosed is a template transfer assembly and method that features a template transfer substrate, and a template having first and second sides, with the first side facing away from the template transfer substrate and the second side facing the template transfer substrate and having mold pattern formed thereon. Polymerized imprint material is disposed between the second side and the template transfer substrate to fixedly attach the template to the template transfer substrate. The method of transferring an imprint lithography template includes dispensing a selected volume of imprinting fluid onto the template transfer substrate, placing the template upon the selected volume; and converting the imprinting fluid to solid imprint material. The selected volume of imprint material is of sufficient quantity to fixedly attach the template to the template transfer substrate while maintaining a space between the mold and the template transfer substrate.

BACKGROUND OF THE INVENTION

The present invention relates generally to imprint lithography. Moreparticularly, the present invention is directed to an assembly andmethod to transfer templates during imprint lithography processes.

Micro-fabrication techniques can produce structures having features onthe order of nanometers. Micro-fabrication is used in a wide variety ofapplications, such as the manufacturing of integrated circuits (i.e.semiconductor processing), biotechnology, optical technology, mechanicalsystems, and micro-electro-mechanical systems (“MEMS”).

Imprint lithography is a type of micro-fabrication technique that isbecoming increasingly important in semiconductor processing and otherapplications. Imprint lithography provides greater process control andreduction of the minimum feature dimension of the structures formed.This in turn provides higher production yields and more integratedcircuits per wafer, for example.

Micro-fabrication can be used to form a relief image on a substrate,such as a semiconductor wafer. The substrate typically has a transferlayer that is coated with a thin layer of polymerizable fluid,thermoplastic, or other imprint material capable of being formed (i.e.molded or imprinted) into a desired structure. A mold with a reliefstructure makes mechanical contact with the substrate and thepolymerizable fluid or other imprint material fills the relief structureof the mold. The polymerizable fluid is then polymerized to form thedesired structure on the transfer layer, which is complimentary to therelief structure of the mold. The transfer layer and the solidifiedpolymeric material can then be etched to form a relief image in thetransfer layer, or coated with a thin-film layer of other material, forexample.

Imprint lithography systems often use an imprint head with a mold, alsocalled a template, which can be installed and removed from the imprinthead. This allows the imprint lithography system to be used to imprintdifferent patterns. In this manner, the imprint lithography system canbe used to fabricate various types of circuits or other devices, orimprint various structures on a substrate.

To ensure high resolution imprinting it is generally desirable tominimize handling of the template in order to avoid damage to thetemplate and contamination to the template and imprint lithographysystem with dust or other particulates. To that end, there is a need tostore, load, and unload templates in a manner that avoids physicaldamage to the relief pattern of the mold and contamination to thetemplate and imprint lithography system.

SUMMARY OF THE INVENTION

A template transfer assembly and method features a template transfersubstrate and a template having first and second sides, with the firstside facing away from the template transfer substrate and the secondside facing the template transfer substrate and having mold patternformed thereon. Polymerized imprint material is disposed between thesecond side and the template transfer substrate to fixedly attach thetemplate to the template transfer substrate. The method of transferringan imprint lithography template includes dispensing a selected volume ofimprinting fluid onto the template transfer substrate, placing thetemplate upon the selected volume and converting the imprinting fluid tosolid imprint material. The selected volume of imprint material is ofsufficient quantity to fixedly attach the template to the templatetransfer substrate while maintaining a space between the mold and thetemplate transfer substrate. These and other embodiments are describedmore fully below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an imprint lithography system forpracticing embodiments of the present invention;

FIG. 2 is a simplified side view of the imprint lithography system,shown in FIG. 1, demonstrating the spatial relationship between the moldand the wafer having imprinting material disposed thereon;

FIG. 3 is a simplified side view of the mold of FIG. 2 in contact withthe imprinting layer;

FIG. 4 is a simplified side view of an imprinting layer, shown in FIG.2, patterned according to the template;

FIG. 5 is a simplified side view of the lithographic system, shown inFIG. 1, with a template transfer holder in a motion stage according toan embodiment of the present invention;

FIG. 6 is a simplified side view of the template transfer holder of FIG.5 in position to load the template in an imprint head;

FIG. 7 is a perspective view showing a template transfer holder of thetemplate transfer system, shown in FIGS. 1, 5 and 6, in accordance withone embodiment of the present invention;

FIG. 8 is a cross-sectional view of the template transfer holder, shownin FIG. 7, taken along lines 8-8;

FIG. 9 is a cross-sectional view of the template transfer holder, shownin FIG. 7, taken along lines 9-9, and having a template disposedtherein;

FIG. 10 is a simplified side view of the template transfer holder, shownin FIG. 7, taken along lines 10-10;

FIG. 11 is a simplified side view of the template transfer holder on atransfer substrate, shown in FIG. 5, according to another embodiment ofthe present invention;

FIG. 12 is a simplified side view of a template transfer holder on atransfer substrate above the wafer chuck, shown in FIG. 5, according toanother embodiment of the present invention;

FIG. 13 is a simplified cross section of a template transfer assemblythat may be employed in the lithographic system, shown in FIGS. 1 and 5,having a template coupled to a template transfer substrate with imprintmaterial according to an embodiment of the present invention;

FIG. 14 is a simplified cross section of a template transfer assembly,shown in FIG. 13, with a template coupled to a template transfersubstrate with a perimeter of imprint material according to an alternateembodiment of the present invention;

FIG. 15 is a simplified cross section of a template transfer assembly,shown in FIG. 13, with a template coupled to a template transfersubstrate with a perimeter of imprint material according to a secondembodiment of the present invention;

FIG. 16 is a simplified cross section of a template transfer assembly,shown in FIG. 13, with a template coupled to a template transfersubstrate with a perimeter of imprint material according to a thirdalternate embodiment of the present invention;

FIG. 17 is a simplified flow chart of a method of handling a template ina lithographic system, shown in FIGS. 1, 2, 3, 4, 5, 11, 12, 13, 14, 15and 16, according to an embodiment of the present invention;

FIG. 18 is a simplified flow chart of a method of removing a templatefrom an imprint head of a lithographic imprinting system, shown in FIG.17, according to another embodiment of the present invention; and

FIG. 19 is a simplified flow chart of a method of installing a templatefrom a template transfer substrate into an imprint head of alithographic imprinting system, shown in FIG. 17, according to yetanother embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a perspective view of an imprint lithography system 10 forpracticing embodiments of the present invention. A pair of spaced-apartbridge supports 12 having a bridge 14 and a stage support 16 extendingtherebetween. Bridge 14 and stage support 16 are spaced-apart. Coupledto bridge 14 is an imprint head 18 that extends from bridge 14 towardstage support 16 and may move along and/or rotate about, X, Y and/or Zaxes. Disposed upon stage support 16 to face imprint head 18 is a motionstage 20 and a template transfer system 40. Motion stage 20 isconfigured to move with respect to stage support 16 along one or moredegrees of freedom. For example, motion stage 20 may move along and/orrotate about, X, Y and/or Z axes. In the present example, motion stage20 holds a wafer 30 on a wafer chuck 21, which is typically a vacuumchuck, and moves wafer 30 along the X and Y axes. A radiation source 22is coupled to imprint lithography system 10 to impinge actinic radiationupon motion stage 20. Radiation source 22 is coupled to bridge 14 andincludes a power generator 23 connected to radiation source 22.

Referring to both FIGS. 1 and 2, a template 26 is removably connected toimprint head 18. Template 26 has first and second sides 26 a and 26 b.First side 26 a faces imprint head 18, and second side 26 b has a mold28 thereon facing away from imprint head 18 toward wafer chuck 21. Mold28 generally includes a plurality of features defined by a plurality ofspaced-apart recessions 28 a and protrusions 28 b, having a step height,h, on the order of nanometers (e.g. 100 nanometers). The plurality offeatures defines an original pattern that is to be transferred onto awafer 30 positioned on motion stage 20. To that end, a distance, d,between mold 28 and a surface 32 of wafer 30 may be varied. It should beunderstood that surface 32 may comprise of material from which wafer 30is formed, including any native oxide formed thereon and/or one or morelayers of material deposited on wafer 30.

An imprinting layer 34 is disposed on wafer 30. Imprinting layer 34 isgenerally a selected volume of imprint material, such as polymerizablefluid, applied to wafer 30, either as a plurality of spaced-apart beads36, as shown, or in a continuous film. Exemplary imprint material isdescribed in U.S. patent application Ser. No. 10/178,947, filed Jun. 24,2002 and entitled “Low Viscosity High Resolution Patterning Material”,which is incorporated by reference herein in its entirety. An exemplarymethod and system for depositing the imprint material is disclosed inU.S. patent application Ser. No. 10/191,749, filed Jul. 2, 2002 andentitled “System and Method for Dispensing Liquids”, which isincorporated by reference herein in its entirety.

Referring to FIG. 3, a simplified side view of mold 28 is shown incontact with imprinting layer 34. Imprinting layer 34 is generallyflowable when mold 28 is brought into contact with imprinting layer 34by creating relative movement between the imprint head 18, shown in FIG.1, and wafer 30 along the Z axis. In the present example, the relativemovement is achieved by moving imprint head 18 along the Z axis. Theimprint material flows to form a contiguous layer that fills mold 28.The imprint material is then converted to a non-flowable (i.e. solid)state, such as by polymerization with actinic radiation, in the case ofa polymerizable fluid imprint material, or by cooling, in the case of athermoplastic imprint material.

FIG. 4 is a simplified side view of imprinting layer 34′ patternedaccording to mold 28. Mold 28 has been removed from imprinting layer 34′by moving the imprint head 18, shown in FIG. 1, away from wafer 30. Astructure 28′ recorded in imprinting layer 34′ is produced, in part, bymechanical contact with mold 28, and is generally an image of mold 28.Wafer 30 with structure 28′ may then be further processed.

Mold 28 has features sized according to the structure 28′ desired to beimprinted to imprinting layer 34′, which can be on the order ofnanometers. It is important to protect mold 28 from physical damageand/or contamination so that the desired structure 28′ is obtained whenimprinting substrates. Template 26 is removable from imprint head 18 ofimprint lithography system 10, shown in FIG. 1. Another template canthen be installed in imprint head 18. For example, if template 26 wearsout or is damaged, a replacement template may be installed, or atemplate with a different mold (i.e. structure or pattern) may beinstalled to imprint a different structure.

Template 26 is removably secured to imprint head 18 with vacuum and/ormechanical means, such as pins or clips. Mechanical means are desirableto ensure retention of template 26 in imprint head 18 in the event of avacuum failure or in the event that vacuum is turned off duringprocessing. Mechanical means of securing template 26 in imprint head 18may also be convenient when installing or removing template 26.

To facilitate coupling template 26 to imprint head 18, the template 26is typically stored on template transfer system 40 so that first side 26a faces imprint head 18. When coupling together template 26 and imprinthead 18, template 26 and imprint head 18 are placed in very closeproximity (e.g. 10's of microns or less) to one another so that thetemplate 26 can be secured to imprint head 18 by vacuum and/ormechanical contact. Manual insertion of the template 26 into imprinthead 18 is typically avoided due to the increased probability of damageto the template 26 and/or imprint head 18, as well as the increasedprobability of contamination of the imprint lithography system 10,particularly the motion stage 20.

Referring to FIG. 5, shown is a simplified side view of a portion ofimprint lithography system 10, shown in FIG. 1, with template transfersystem 40 on a motion stage 20, according to an embodiment of thepresent invention. Template transfer system 40 may be permanentlyaffixed to motion stage 20, or alternatively, may be removably mountedto motion stage 20. An advantage of template transfer system 40 beingpermanently affixed to motion stage 20 is that the position of templatetransfer system 40 is precisely repeatable. An advantage of templatetransfer system 40 being removably attached to motion stage 20 is thattemplate transfer system 40 may be removed after installing template 26into imprint head 18, which reduces the mass of motion stage 20 andtherefore does not affect stage performance during imprinting.Similarly, sensors and vacuum conduits might be more easily implementedif template transfer system 40 is permanently affixed to motion stage20, and would not require attachment or alignment mechanisms torepeatedly install template transfer system 40 on motion stage 20.

It is generally desirable that template transfer system 40 be located ina position on motion stage 20 that allows template transfer system 40 tobe brought to a convenient position for loading template 26 intotemplate transfer system 40, and then to be brought underneath imprinthead 18 without compromising wafer imprinting. Many motion stages have arange of motion greater than the range required to imprint the entiresurface of a wafer 30, shown in FIG. 1, mounted on wafer chuck 21, andallow mounting template transfer system 40 on a portion of motion stage20 that is accessible by imprint head 18, but that does not interferewith wafer imprinting.

Referring to FIG. 6, shown is a simplified side view of templatetransfer system 40 of FIG. 5, in position to load template 26 in imprinthead 18. To that end, motion stage 20 has been moved so that template 26in template transfer system 40 is beneath imprint head 18. Imprint head18 includes a pocket 42 or other structure for receiving template 26.Vacuum and/or mechanical retention means for holding template 26 inimprint head 18 are omitted for simplicity of illustration. Imprint head18 and template 26 are placed in close proximity to one another, andtemplate 26 is securely retained in imprint head 18.

After loading template 26 into imprint head 18, the relative positionsof imprint head 18 and motion stage 20 are established to imprint awafer (not shown) loaded onto wafer chuck 21. Upon completion ofimprinting processes, template 26 may be removed from imprint head 18 byreversing the sequence of loading steps, and load another template intoimprint head 18, if desired.

Referring to FIGS. 1, 2 and 7, important characteristics demonstrated bytemplate transfer system 40 is to prevent movement of template 26 whenhoused therein, as well as to prevent mold pattern 28 from being damagedand minimize particulate contamination as a result of movement of thetemplate 26 to and from template transfer system 40. To that end,template transfer system 40 includes a template transfer holder 40 aand, optionally, a template transfer gimbal 40 b. Template transfergimbal 40 b allows angular movement of template transfer holder 40 aabout three orthogonal axes.

Template transfer holder 40 a includes a body 50 having a plurality oftines 52 extending from a common side 54 of body 50. Also protrudingfrom side 54 is a plurality of compliant members 56, each of which has athroughway 58. Throughway 58 is in fluid communication with a channel60, shown in FIG. 8, extending from side 54 into body 50. A centralchannel 62 is in fluid communication with one or more exit channels 64that have couplings 66 connected to a side 68 of body 50 disposedopposite to side 54. Couplings 66 facilitate connecting channels 60 to apump system 70 via elastic tubing 67 coupled between channels 60 andcouplings 66. Pump system 70 may create vacuum or positive pressure,dependent upon the application.

Referring to FIGS. 7 and 8, each of tines 52 includes an oblique surface52 a that is substantially smooth. Oblique surface 52 a extends from afirst end 52 b of tine 52, disposed opposite to side 54 and extendstoward a second end 52 c of tine 52 positioned between oblique surface52 a and end 52 b. End 52 c is coupled to, or integrally formed with, aresilient member 53 coupled between body 50 and tine 52. Side 54 extendsfrom end 52 b and angles inwardly toward the tine 52 disposed on anopposite edge of body 50. In this manner, a length l₁ between ends 52 bof opposed tines 52 is greater than a length l₂ between ends 52 c ofopposed tines 52. The dimensions of l₂ are established to be slightlylarger than the template 26, shown more clearly in FIG. 9. Referring toboth FIGS. 8 and 9, resilient member 53 includes a body 53 a having avoid 53 b formed therein. A detent 53 c is positioned proximate to end52 c and extends therefrom to selectively contact a perimeter region 26d of template 26. In superimposition with detent 53 c is a gap 53 dextending through body 53 a into void 53 b to facilitate bending ofresilient member 53 about pivot point 53 e. Pivot point 53 e ispositioned substantially opposite to gap 53 d, and a moment arm 53 fextends between detent 53 c and pivot point 53 e. Tine 52 rests uponmoment arm 53 f.

Referring to both FIGS. 8 and 9, oblique surfaces 52 a function to guidetemplate 26 onto template transfer holder 40 a, shown in FIG. 1, so asto minimize frictional contact with template 26. To that end, tines 52,shown in FIG. 7, are formed from a compound having minimal friction,such as a Teflon®-containing material, e.g., a PTFE-filled Acetal. Anexemplary material is sold under the tradename Delrin AF®, availablefrom DuPont®. Resilient members 53 are structured to allow tines 52 tobend toward template 26 and clamp against template edge 26 c to centertemplate 26 on transfer template holder 40 a.

Referring to FIGS. 8, 9 and 10, to facilitate clamping of template 26 bytines 52, shown in FIG. 7, compliant members 56 are formed from DelrinAF® and include a suction cup 56 a and a detent 56 b disposed oppositeto suction cup 56 a. Body 50 includes a chamber 55 in which a boss 56 cis disposed, with detent 56 b being disposed in chamber 55 resting onboss 56 c. The volume of chamber 55 is greater than the volume of eitherdetent 56 b or boss 56 c, allowing the same to move freely withinchamber 55 along three orthogonal axes. Chamber 55 includes an opening55 a disposed in side 54 through which a sub-portion of compliant member56 passes to allow suction cup 56 a to extend from side 54. However, thecross section of opening 55 a is less than a cross section of boss 56 c.As a result, the region of body 50 surrounding opening 55 a forms abearing surface 55 b against which boss 56 c bears when a vacuum isapplied to template 26. Boss 56 c is coupled to a channel 60 thatextends through chamber 55. Detent 56 b is resiliently biased against aportion of boss 56 c positioned proximate to opening 55 a. In thismanner, compliant member 56, boss 56 c and channel 60 move as a unitwithin chamber 55. In the absence of a vacuum, boss 56 c rests against abushing 56 d disposed in chamber 55 to maintain boss 56 c within chamber55. An interface 56 e of a surface of boss 56 c and a surface of bushing56 d has a frusto-conical shape that is symmetrical about an axis 55 cof chamber 55. The frusto-conical shape of interface 56 e centerssuction cup 56 a with respect to chamber 55. To that end, tubing 67functions as a dead weight under force of gravity g, pulling channel 60downwardly. Upon application of a vacuum to template 26, pump system 70operates to evacuate central channel 62, thereby exerting a compressionforce between compliant member 56 and template 26. The compression forceurges boss 56 c against bearing surface 55 b. Once boss 56 c bearsagainst bearing surface 55 b, movement along Z axis is minimized, if notprevented. However, boss 56 c may still move along the X and Y axes.

As a result of compression of template 26 against compliant members 56,a perimeter region 26 d of template 26 bears against detent 53 c andmoves along the Z axis about pivot point 53 e. Member arm 53 fcantilevers toward surface 52 a causing end tines 52 to move inwardlytoward template 26 until template edge 26 c is compressed by ends 52 c.Each of tines 52 is arranged to move approximately the same extent asthe remaining tines 52 on body 50. The free movement of detent 56 b andboss 56 c along X and Y axes, as well as the movement of tines 52,results in template 26 being placed at a predefined location on body 50,each time template 26 is loaded thereon. In the present example,template 26 is centered on body 50. This is referred to as the finalseating position. In the final seating position, mold 28 is spaced-apartfrom side 54. To that end, gap 53 d is provided with a height h₁, andmold 28 extends from side 26 b having a height, h₂. Heights h₁ and h₂are established to ensure that upon reaching the final seating positionmold 28 does not contact surface 52 a. Thus, the structural integrity ofmold 28 is preserved, while allowing template 26 to be removed andinserted into template transfer holder 40 a with imprint head 18, shownin FIG. 1.

Referring to FIGS. 1 and 11, shown is a simplified side view of atemplate transfer system 140 that is removably mounted to motion stage20. Template transfer system 140 includes a transfer substrate 144, andtemplate 126 may be affixed thereto using imprint material, discussedmore fully below. Transfer substrate 144 can be made from any of avariety of materials, such as aluminum, stainless steel, glass, ceramic,silicon and the like. Further, the transfer substrate 144 may be biggeror smaller than the production wafers (substrates) that will beimprinted. A transfer substrate 144 that is the same size as productionwafers enables using the alignment structure on wafer chuck 21, normallyused for production wafers. With this configuration, transfer substrate144 is compatible for use with existing wafer handling systems, e.g.,robots, cassettes and the like. This is beneficial because template 126and transfer substrate 144 may be manipulated using a wafer handlingsystem, instead of manually.

Template transfer system 140 can be located anywhere on transfersubstrate 144 accessible by the imprint head 18. Motion stage 20 doesnot need additional motion range to position template transfer system140 under imprint head 18. Contamination of wafer chuck 21 by thebackside of transfer substrate 144 may be reduced by proper handling oftransfer substrate 144.

Referring to FIGS. 1 and 12, shown is a simplified side view of atemplate transfer system 240 on a transfer substrate 244 spaced-apartfrom wafer chuck 21, according to another embodiment of the presentinvention. The position of template 226 and template transfer substrate244 may be fixed employing imprint material, discussed more fully below.Legs 246 support transfer substrate 244 above wafer chuck 21, therebyavoiding contamination of the surface of wafer chuck 21 from contactwith the backside of transfer substrate 244 (i.e. the side oppositetemplate transfer system 240). Alternatively, legs 246 that extend fromtransfer substrate 244 onto a perimeter region of wafer chuck 21, or aperimeter ledge or other structure, are used to support transfersubstrate 244 above wafer chuck 21.

Referring to FIGS. 1 and 13, shown is a simplified cross section of atemplate transfer assembly 340 having template 326 coupled to a templatetransfer substrate 344 with solid imprint material 334, according to anembodiment of the present invention. Template transfer substrate 344could be a process wafer, for example. Template 326 is stored ontemplate transfer substrate 344 when not in use, and template 326 can beloaded from template transfer substrate 344 into imprint head 18.

When it is desired to unload and store template 326 from imprint head 18(e.g. after imprinting a run of process wafers), template transfersubstrate 344 is mounted on wafer chuck 21. A selected volume ofimprinting material is applied in a fluid state to the region oftemplate transfer substrate 344 that template 326 will be attached to.The volume of fluid may be less than, the same as, or greater than thevolume of imprinting material that would be used to imprint a productionwafer.

Template 326 is brought into contact with the imprinting material, andthe imprinting material is polymerized or otherwise solidified fixedlyaffixing template 326 to template transfer substrate 344. Rather thanincreasing a distance between the imprint head 18 and the wafer chuck21, vacuum and/or mechanical retaining means may be deactivated torelease template 326 from the imprint head 18. Template 326 adheres totemplate transfer substrate 344 with solid imprint material 334, and maybe moved therewith to a remote storage location.

Alternatively, template transfer substrate 344 may be left on the waferchuck 21 and template 326 is removed from or retained in the imprinthead 18. In each case, solid imprint material 334 protects the moldpattern 328 on template 326 when not in use. Solid imprint material 334seals template 326 from contamination and the mold pattern 328 on theface of template 326 is protected from damage. This may be achieved bycovering the entire area of mold pattern 328 with the imprint material334, thereby hermetically sealing mold pattern 328.

When template 326 is removed from the imprint head 18 for storage again,a new or reworked template transfer substrate is used. Alternatively,the same substrate may be employed to store template 326, but thetemplate 326 would be stored in a differing region thereof. A templatetransfer substrate 344 is reworked by removing solid imprint material334 from template transfer substrate 344. Process wafers rejected beforeimprinting are often convenient for use as template transfer substrates344.

Alternatively, as shown in FIG. 14, template transfer holder 440 mayinclude having imprinting material 434 applied to a sub-portion 428 a ofmold pattern 428. To that end, the imprint material 434 is applied insufficient quantity to allow sub-portion 428 a to be spaced-apart fromboth the template transfer substrate 444 and the imprint material 434.Further, by circumscribing sub-portion 428 a with imprinting material434, sub-portion 428 a may be encapsulated, e.g., hermetically sealed sothat the only atmosphere to which mold pattern 428 is exposed is presentin volume 434 a to which sub-portion 428 a is exposed. This preventsingress of contamination into sub-portion 428 a of mold pattern 428during storage.

When it is desired to store template 426, the same may be attached totemplate transfer substrate 444 with solid imprint material 434 tofixedly attach template transfer substrate 444 to template 426. To thatend, template transfer substrate 444, having imprinting material 434, isloaded onto the wafer chuck 21 and template 426 is moved to a positionunderneath the imprint head 18 (if not already loaded). Relativemovement between the imprint head 18 and template 426 is achieved toreduce the spacing therebetween, placing the imprint head 18 and thetemplate 426 in close proximity or contact. The template 426 is securedto the imprint head 18 by means of a vacuum and/or mechanical coupling.The imprint head 18, along with template 426 is placed insuperimposition with template transfer substrate 444. Thereafter,contact is made between template 426 and imprint material 434 present ontemplate transfer substrate 444. The imprint material 434 is thensolidified, as discussed above, securely affixing template 426 totemplate transfer substrate 444.

Referring to FIG. 15, shown is a simplified cross section of a templatetransfer holder 540 having a template 526 coupled to the templatetransfer substrate 544 with a perimeter of solid imprint material 534according to another embodiment of the present invention to fixedlyattach template transfer substrate 544 to template 526. In thisconfiguration, the entire mold pattern 528 may be encapsulated, e.g.,hermetically sealed as discussed above with respect to FIG. 14. Further,template 526 may, optionally, include a perimeter mesa 536 that forms aperimeter recess 537 around the mold pattern 528. Imprint material 534does not adhere to a mold pattern 528 on template 526, thus facilitatingmold fidelity.

To store template 526 on template transfer substrate 544, a selectedvolume of imprinting material 534 is applied in a fluid state to asurface 531 of template transfer substrate 544. The imprinting material534 may be applied to a selected area (e.g. an area corresponding to theperimeter of template 526), or the volume of imprinting material 534 isselected to adhere to the perimeter mesa 536 only, and to not fill inareas of mold pattern 528 on template 526. Recess 537 prevents fluidimprinting material 534 from reaching mold pattern 528 when mechanicalcontact is made between the imprinting material 534 and template 526.

FIG. 16 is a simplified cross section of a template transfer assembly640 having a template 626, a mesa 636 and a major surface 626 a disposedopposite to the mesa 636. A mold pattern 628 is included on the mesa 636as having grooves 628 a and protrusions 628 b. The grooves 628 a includea nadir surface 628 c and the protrusions 628 b include an apex surface628 d. A surface 638 circumscribes, if not all, then a subset of thegrooves 628 a and the protrusions 628 b. One or more of nadir surfaces628 c are spaced apart from major surface 626 a a first distance d₁, andone or more apex surfaces 628 d are spaced-apart from major surface 626a a second distance, d₂. Surface 638 is spaced apart from major surface626 a a third distance, d₃. Mesa 636 is defined by ensuring thirddistance d₃ differs from both first and second distances, d₁ and d₂. Inthe specific example, distance d₃ is less than either of distances d₁and d₂. Imprinting material 634 is disposed in regions between surface638 and surface 631 of template transfer substrate 644. In this fashion,imprint material 634 may be employed to maintain a fixed positionbetween template 626 and template transfer substrate 644 without imprintmaterial 634 contacting mold pattern 628 on template 626. Additionally,imprinting material 634 may be disposed so as to encapsulate moldpattern 628, e.g., hermetically seal the same, as discussed above. Inthis manner, mold pattern 628 is protected from physical damage andcontamination.

To store template 626 a selected volume of imprinting material 634 isapplied in a fluid state to a surface 631 of template transfer substrate644. The imprinting material 634 is applied to a region of surface 631that will be in superimposition with surface 638. The volume ofimprinting material 634 typically selected is sufficient to adheretemplate 626 to the template transfer substrate 644 so that mold pattern628 is spaced-apart from surface 631. Although it is not necessary,imprinting material 634 may circumscribe mold pattern 628, therebyencapsulating the same to prevent contamination by particulate matter.

Referring to FIGS. 1 and 17, during operation of imprint lithographysystem 10, template 26 is loaded onto template transfer system 40 atstep 702. Template 26 is moved to a position beneath an imprint head 18at step 704 and the spacing between the imprint head 18 and template 26is reduced at step 706 to place the imprint head 18 in close proximity,or in contact, with the template 26. The template 26 is secured to theimprint head 18 at step 708, and the distance between template transferholder 40 a and imprint head 18 is increased at step 710. The templatetransfer holder 40 a is moved to a second position that is not beneaththe imprint head 18 at step 712. In a further embodiment, the templatetransfer holder 40 a is removed from the motion stage 20 at step 714 anda process wafer 30 is loaded on a wafer chuck 21 of the motion stage 20for imprinting with the template 26. Although the foregoing has beendiscussed with respect to template transfer system 40, it should beunderstood that the operation discussed with respect to FIG. 17 applieswhen using template transfer systems, 140, 240, 340, 440, 540 and 640,shown in FIGS. 11, 12, 13, 14, 15 and 16, respectively.

FIG. 18 is a simplified flow chart of a method 720 of removing atemplate 26, shown in FIG. 1, from an imprint head 18 in an imprintlithography system 10, according to another embodiment of the presentinvention. A template transfer substrate, such as template transfersubstrates 144, 244, 344, 444, 544 and 644, shown in FIGS. 11, 12, 13,14, 15 and 16, respectively, may be employed. For simplicity ofdiscussion, the present example is discussed with respect to templatetransfer substrate 444, shown in FIG. 14, and applies with equal weightto the aforementioned template transfer substrates. At step 722,template transfer substrate 444 is loaded onto a wafer chuck 21 inimprint lithography system 10. A selected volume of imprinting fluid isdispensed onto the surface of the template transfer substrate 444 atstep 724. Relative movement between the imprint head 18 holding atemplate 26 and the template transfer substrate 444 is achieved so thatthe template 26 contacts the imprinting fluid at step 726. Theimprinting fluid is converted to solid imprint material at step 728. Thetemplate 26 is released from the imprint head 18 (e.g. by turning offthe securing means and raising the imprint head 18) and the templatetransfer substrate 444 with the attached template 26 is removed from thewafer chuck 21 and transferred to a storage location at step 730.Alternatively, the template 26 remains attached to the template transfersubstrate 444 on the wafer chuck 21 and the imprint head 18 and thetemplate 26 are arranged to be spaced-apart at step 730 a. In yetanother alternative, the template 26 is left in the imprint head 18attached to the template transfer substrate 444 for storage on the waferchuck 21 at step 730 b.

FIG. 19 is a simplified flow chart of a method 740 of installing atemplate 26, shown in FIG. 1, from a template transfer substrate 444,shown in FIG. 14, into an imprint head 18 of an imprint lithographysystem 10, according to yet another embodiment of the present invention.A template transfer substrate 444 with a template 26 adhered to thetemplate transfer substrate 444 with imprint material 434 is provided atstep 742. The template transfer substrate 444 is loaded onto a waferchuck 21 of a wafer 30 in imprint lithography system 10 at step 744.Alternatively, the template transfer substrate 444 is already on thewafer chuck 21, as when the template 26 is stored in this fashionbetween uses. The wafer chuck 21 is moved to position the template 26beneath an imprint head 18 of the wafer 30 in imprint lithography system10 at step 746. Alternatively, a template 26 stored on a templatetransfer substrate 444 is already beneath the imprint head 18. Relativemovement between the imprint head 18 and the template 26 is achieved toplace the imprint head 18 and template 26 in close proximity or contactat step 748. The template 26 is secured to the imprint head 18 at step750. The distance between imprint head 18 and template transfersubstrate 444 is increased at step 752, releasing the template 26 fromthe imprint material 434. The template transfer substrate 444 is removedfrom the wafer chuck 21 and a process wafer 30 may then be loaded ontothe wafer chuck 21 for imprinting with the template 26.

The embodiments of the present invention described above are exemplary.Many changes and modifications may be made to the disclosure recitedabove, while remaining within the scope of the invention. Therefore, thescope of the invention should be determined not with reference to theabove description, but instead should be determined with reference tothe appended claims along with their full scope of equivalents.

1. A template transfer assembly comprising: a template transfersubstrate; a template having first and second sides, with said firstside facing away from said template transfer substrate and said secondside facing said template transfer substrate and having a mold patternformed thereon; and polymerized imprint material disposed between saidsecond side and said template transfer substrate to fixedly attach saidtemplate to said template transfer substrate.
 2. The template transferassembly as recited in claim 1 wherein said polymerized imprint materialsurrounds a sub-section of said mold.
 3. The template transfer assemblyas recited in claim 1 wherein said polymerized imprint materialhermetically seals a sub-portion of said mold.
 4. The template transferassembly as recited in claim 1 wherein said polymerized imprint materialsurrounds said entire mold.
 5. The template transfer assembly as recitedin claim 1 wherein said polymerized imprint material encapsulates saidentire mold hermetically sealing said mold from an ambient.
 6. Thetemplate transfer assembly as recited in claim 1 wherein said templatefurther includes a perimeter groove surrounding said mold with saidpolymerized imprint material disposed between said template transfersubstrate and a region of said second side that is in superimpositionwith said perimeter groove.
 7. The template transfer assembly as recitedin claim 1 wherein said template transfer substrate comprises asemiconductor wafer.
 8. The template transfer assembly as recited inclaim 1 wherein said template transfer substrate includes asemiconductor wafer having an additional template coupled thereto.
 9. Atemplate transfer assembly comprising: a template transfer substrate; atemplate having first and second sides, with said first side facing awayfrom said template transfer substrate and said second side facing saidtemplate transfer substrate and having a mold formed thereon; andpolymerized imprint material disposed between said second side and saidtemplate transfer substrate to fixedly polymerized imprint materialdisposed between said second side and said template transfer substrateto fixedly attach said template to said template transfer substratewhile maintaining a space between said mold and said template transfersubstrate.
 10. The template transfer assembly as recited in claim 9wherein said space is filled with imprint material.
 11. The templatetransfer assembly as recited in claim 9 wherein a sub-portion of saidspace defines a void between said substrate and a sub-section of saidmold.
 12. The template transfer assembly as recited in claim 11 whereinsaid polymerized imprint material surrounds said void.
 13. The templatetransfer assembly as recited in claim 9 wherein said polymerized imprintmaterial hermetically seals a sub-portion of said mold.
 14. The templatetransfer assembly as recited in claim 11 wherein said void iscoextensive with said mold.
 15. The template transfer assembly asrecited in claim 9 wherein said polymerized imprint materialencapsulates said entire mold hermetically sealing said mold from anambient.
 16. A method of transferring an imprint lithography template,said method comprising: providing a template transfer substrate; forminga selected volume of imprinting fluid onto said template transfersubstrate; placing said template upon said selected volume; andconverting said imprinting fluid to solid imprint material, with saidselected volume being a quantity sufficient to fixedly attach saidtemplate to said template transfer substrate while maintaining a spacebetween a mold and said template transfer substrate.
 17. The method asrecited in claim 16 wherein converting further includes urging saidtemplate upon said selected volume so that, upon converting said imprintmaterial, said solid imprint material surrounds a portion of said mold.18. The method as recited in claim 10 wherein converting furtherincludes urging said template upon said selected volume so that, uponconverting said imprint material, said solid imprint materialhermetically seals a sub-portion of said mold.
 19. The method as recitedin claim 10 wherein converting further includes urging said templateupon said selected volume so that, upon converting said imprintmaterial, said solid imprint material surrounds said mold, entirely. 20.The method as recited in claim 10 wherein converting further includesurging said template upon said selected volume so that, upon convertingsaid imprint material, said solid imprint material encapsulates saidmold, hermetically sealing said mold from an ambient.